As disclosed in JP,A 61-251440, for example, a rotor of a conventional induction electric motor having a relatively small capacity comprises a rotor core, conductor bars, and end rings. The rotor core is formed by stacking a plurality of silicon steel sheets one above another, and a plurality of conductor bars are arranged in holes formed in the rotor core. The end rings are fixed to opposite ends of the conductor bars. The conductor bars and the end rings are made of aluminum or an aluminum alloy. The conductor bars and the end rings are integrally molded by die casting with high mass production.